Thermostatic switch



Allg- 23 1927' E. sTRANszKY THERMOSTATI C SW1 TC H` Orizinal Filed Deo. 8. 1921 @gyn y /5 /yx l /5 Y r g@ Hm K f ,//w

Q Q #j mvnrrori ATTORNEY Patented Aug. '23,'4 1927.

UNITED STATES l [1,646,251 PATENT OFFICE,l

EMIL sTEANszxY, E wnnnEN, PENNSYLVANIA, AssIGNon To EEANE E. RAVE, Jn., 4um E. e. x, ME1srEE,EoTH or CLEVELAND, omo. 1

THEEMos'rA'rIc SWITCH.

Original application led December 8, 1921, Serial No. 520,970. Divided and this application led october a1,- 1922;

i The object of my -said invention is the provision of a. thermostatic switchh slmple in construction and positive and reliable in action and designed to be used to advantage in electric irons and heating appliances and electric water heaters, and for controlling gas, steam valves, and refrigerators and the temperature' of apartments and the l1ke.

To the attainment of the foregoing, the invention consists in the improvement as hereinafter described and definitely clanned. In vthe accompanying drawings, forming part of this specicationz- Fi re. 1 .is a view of a thermostatic switc .constructed in accordance with my invention and designed more partlcularly fonnse in theelectrically-heated fiat iron constituting the subject'of my Vcontemporary application filed December 8, 1921, Serial No. 520,970 from-y which said switch is divided as an invention separate from theV iron.

Figures .2 and 3 are views of modified switches also divi-ded from4 said identified 25 application.

Figures 4, 5, 6` and 7 are views of other modified switches constructed in accordance with my invention. I

For conveniencein description reference 30. will first be made to Figure 1.

The thermostatic switch illustrated 1n Figure 1 and which I have successfully used in actual practice is made up of a bar 11, a bar 12x spaced from the bar 11, a body of insulating material 13 interposed between and connected with the bars 1'1 and 12", a thin metallic strip 14 superimposed on the bar 11 and also connected with the body of insulation 13, a contact protuberance 15 at the underside of the free portion of the bar 12 and a. screw 16 adjustably connected with the free portion of the bar 11 and having a head adaptedto engage the free end of the thin strip 14 and cooperate therewith for a purpose hereinafter set forth. At this point I would have it understood that the bar 11 is composed Aof two metals 17 and 18 one of which is less amenable to the action of heat than theother, this in order to' 5 render the bar more prompt in action; also, that the lower member 18 is transversely kerfed at its underside as indicated by 19 so that strain is taken off the connecting Seiri'al N0. 596,087.

screw 20 incident to bending of the bar 11. The thin stri 14 is possessed of resiliency, and is norma ly arranged against the contact protuberance 15, it being understood in this connect-ion that the bars 11 and 12x are interposed between and electrically connected with the heating element such as a resistance coil and a source of electric energy. With this understanding, it will vbe further understood that when the bar 11 is subjected to the action of, heat to a predetermined'extent, the sa-id'heat will have the effect of .causing the free portion of the bar 11 to move away from the free portion of the bar 12x so that the head. of the screw 16 will' engage and draw the strip 14 out of contact with the rotuberance 15. In this way the supply of) current to the heating element alluded to will be cut off until the temperature of the thing heated bythe heating element is reduced to a predeterminedy extent when the bar 11 will be restored to its normal state, and incident to such restoration the strip 14 will be carried against the protuberance 15 and the supply of current to the referred to heating element will be reestablished. From this it`follows that by novel thermostatic switch when used in plication will reliably maintain the tempera.

ture of the ironing surface of theriron at a uniform degree so that the iron will op# crate efficiently, and yet there will be no liability of the said ironing surface being unduly heated so that the fabric being ironed will be scorched.

The thermostatic switches shown in Figures 2 and 3 lack 'the screw 16 before described. In lieu of the said screw 16 the bar 11a in each of the said-switches has at its free end a hook 16a which is designed to cooperate with the strip 14a in the same manner that the head of the screw 16 co operates with the thin strip 14. It Will also be noted by particular reference to Figure 2 that the bars 11 and 12a have terminals 22a and 23a arranged as shown relative to a body of insulation 13a, and that the said bars 11a and 12a are connected together f and 23b are arranged as illustrated as is also the connecting means It will be understood, however, that the operation of each of the modifications in Figures 2 and 3 is generally similar to the operation of the embodiment shown in Figure 1 and that the modifications are possessed of all of the practical advantages hereinbefore ascribed to the embodiment in Figure 1.

The embodiment shown in Figure 4 is substantially the same constructionas in Fig- Vlli ure 1 but in inverted position, the bar 11 being arranged above instead of below the bar 12x and being devoid of the kerf 19, Figure 1, as are also the bars 11 and 11h of Figures 2 and'3, respectively. ySaid bar 11, however, is composed of two metals 17 and 18 one of which is less amenable to the actionof heat than the other in order to render the bar more prompt in action. It will be noted, however, in respect to Figure 4 that in lieu of using the head of the adjustable screw 16 to engage the thin strip 14 and separate the contact 14d thereon from the contact 14 on the bar 12, the screw 16 is equipped for the purpose with an enlargement 16d. The bar 11 works upwardly for the separation of the contacts 14d and 14. The bar 11, the strip 14 and the bar 12f are connected to insulating maj terial 13, and the heel portions of the bar 11 and the thin strip 14 are also insulated from each other as shown.

In the modification shown in Figure 5, the thermostatic bar--i. e., the bar which opens and closes the circuit is designated by 11d and is of the same construction as the bar 11 in the respect of including the two metals 17 and 18 one of which is less amenable to the actionA of heat thanthe other. The said bar 11l is insulated at 40 from the switchand is arranged on downl ward movement to open the circuit. The

advantage peculiar to this construction resides in the fact that, thecontacts 14.t and 14g can be separated'more qu'ickly than in .the construction shown'in Flgure 4 for the reason that the said thermostatic bar can act against resilient strip 14rx at any convenient point, the screw 16 of the bar 11'l being provided with a shoe 41 to engage the thin resilient strip 14h and being arranged to work through an opening in the bar 12K. A set screw 42 is employed on one of the contacts-i. e., the contact 14 to put more tension on the switch, said screw being threaded through strip 12B and connected to contact 14.

In the embodiment shown in Figure 6 the adjustmentl is made on the switch as a unit by moving the switch closer to or farther l from the thermostatic bar 11", the said bar 11l being formed of two metals 17 and 18 one of which is less amenable to the action of heat than the other and being provided with a hook 11j preferably of insulating material. The switch contacts 141 and 14j are carried by a thin resilient stri 14k and a bar 12", respectively, and the said) strip and bar are carried by a lever member 43, preferably of insulating material. The thermostatic bar 11 is solidly fastened at 44, and the switch portions are separately mounted as stated s0 that by adjusting the lever member 43 and adjustably fix-ing the same the free end of the thin strip 14K can be positioned at various distances from the hook 1114. This thermostatic switch is susceptible of use to advantage for closing and opening anI electric circuit complementary to a refrigerating system, :md I prefer to adjust and adjustably fix the lever member 43 through the medium of the handle-pointer 53, Fi vures 6 and 7, fulcrumed on a pin 54 carrie by support 55, and having an ,irregular slot 56 that receivesa heel pin 57 on the lever member 43. The handle pointer is by preference relatively arranged as shown` to an arcuate scale 58, Fi ure 7, so that the extent fof adjustment can e readily determined.

Manifestly my novel switch can be used in any position to suit ditl'erentconditions. I would also have'it understood that in using the thermostatic switch ina direct current I connect a condenser in proper relation across the contacts in order to reduce the arc when the circuit is open. I have deemed it unnecessary, however, to illustrate the condenser and the connection thereof herein.

Having described my invention, what I claim and desire to secure by Letters-Patent, 1s:

A switch of the classV described including a stationary, support, a thermostatic bar formed of two metals, one of which is less amenable to the action of heat than the other, a hook dependin from the outer end of said bar, a lever mem r pivotally mounted on the su ort beneath the thermostatic bar, a secondphar detachably secured to the under side of thelever at one end. thereof, a resilientv stri detachably secured to the opposite side of) the bar and insulated therefrom, and both said bar and strip having engaging contacts at the outer end, the outer end of said strip being positioned in the path of said hook, and a heel pin connected with thel other end of the said lever connecting the lever member with a handpointer..

EMIL s'rRANszKY. 

